This study examines the extent to which personality traits and intelligence scores predict school level academic performance (AP), (British GCSE: General Certificate of Secondary Education; America Grade 10) in different disciplines. The participant sample consisted of approximately 250 school pupils from three schools in the South East of England. A series of hierarchical regressions were performed with participant discipline-specific subject grades being the criterion variable and demographic, as well and intelligence and personality test scores, the predictor variables. For overall grade intelligence accounted for a fifth of the variance and personality an incremental validity of 8%. Whilst a combination of intelligence, personality and sex accounted for around a quarter of the variance in all four core subjects the pattern was rather different for elected subjects. The results are discussed in terms of the usefulness of psychometric assessments of candidates at selection. (Contains 4 tables.)